【Java学习20170411】反射+Json解析

第七章

1、反射：

1）、用来实心动态代理；

2）、在运行过程中动态获取对象的类型；

3）、在运行过程中，动态加载对象；

4）、在运行过程中，动态的调用对象的方法；

5）、常常用来实现框架

2、Object是所有类型的父类，Java所有类型，包括自定义类型都默认继承Object

3、Class类型：反射技术的核心类，通过这个类，完成所有反射技术的实现，获取class对象的三种方法：类型.class：获取该类型的class对象

获取某个类型的class对象的方法：通过类型的对象.个体Class()

forName：Class类型的静态方法，通过字符串获取某一个的类型的class对象

package com.share.test_4_11;public class Student extends Person{private String name;private int age;public char sex ;public static int i;public Student(String name,int age,char sex){this.name = name;this.age = age;this.sex = sex;}public Student(String name,String[] i){this.name = name;}public Student(){name ="sb111";age = 11;sex = '男';}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overridepublic String toString() {// TODO Auto-generated method stubreturn "name:"+name+"   age:"+age +"   sex:"+sex;}}

package com.share.test_4_11;import java.lang.reflect.Constructor;import java.lang.reflect.Field;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;public class Person {public static void main(String[] args) {try {Class<Student> c = (Class<Student>) Class.forName("com.share.test_4_11.Student");System.out.println(c.getName());Student s =  c.newInstance();//Student一定要包含一个无参的构造方法System.out.println(s);Constructor<?>[] c1 = c.getConstructors();//返回公共的构造方法System.out.println("构造方法个数："+c1.length);for (int i = 0; i < c1.length; i++) {System.out.println("---构造方法----");System.out.println(c1[i].toString());Class<?>[] c2 = c1[i].getParameterTypes();//获得这个构造方法的参数列表System.out.println("c2:"+c2.length);for (int j = 0; j < c2.length; j++) {System.out.println(c2[j].getName());}}Class<? super Student> superclass = c.getSuperclass();//返回当前类型的父类型System.out.println(superclass.getName());Class<?> superclass2 = superclass.getSuperclass();//如果没有父类，返回null//System.out.println(superclass2.getName());System.out.println("-------方法--------");Method[] m = c.getDeclaredMethods();for (int i = 0; i < m.length; i++) {System.out.println(m[i].toString());}Method m1 = c.getMethod("setAge",int.class);System.out.println(m1.getName());m1.invoke(s, 100);//私有方法怎么执行？？？？？？？？？？？、setAccessibleSystem.out.println("-----属性-----");Field[] f = c.getDeclaredFields();for (int i = 0; i < f.length; i++) {System.out.println(f[i].toString());}f[2].set(s, '女');//私有属性怎么修改？？？？？？？？？？？？？？？System.out.println(s);System.out.println("属性值为："+f[2].get(s));f[1].setAccessible(true);//修改私有属性！！！f[1].set(s, 250);System.out.println(s);System.out.println("属性值为："+f[1].get(s));} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (InstantiationException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalAccessException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (NoSuchMethodException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SecurityException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalArgumentException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (InvocationTargetException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

Json解析

列1：

package com.share.test_4_11;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.URL;public class HttpGetTest {public static void main(String[] args) {HttpGetTest get = new HttpGetTest();try {get.t();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public String t() throws IOException{URL url = new URL("http://172.18.6.3:8080/PunishmentVote/vote?result=1");InputStream is = url.openStream();InputStreamReader isr = new InputStreamReader(is,"UTF-8");BufferedReader in = new BufferedReader(isr);StringBuffer sb = new StringBuffer();String inputLine;while ((inputLine = in.readLine())!=null) {sb.append(inputLine);System.out.println(inputLine);}in.close();return sb.toString();}}

package com.share.test_4_11;public class Tangxin {private String vote_result;private String result;public String getVote_result() {return vote_result;}public void setVote_result(String vote_result) {this.vote_result = vote_result;}public String getResult() {return result;}public void setResult(String result) {this.result = result;}}

package com.share.test_4_11;import java.io.IOException;import com.google.gson.Gson;public class JsonTest {public static void main(String[] args) {HttpGetTest t = new HttpGetTest();String ht;try {ht = t.t();Gson gson = new Gson();Tangxin tx = gson.fromJson(ht, Tangxin.class);System.out.println(tx.getResult());System.out.println(tx.getVote_result());} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

列2

package com.share.test_4_11;import java.util.List;import com.google.gson.Gson;public class ZuoYe {/* * 字符串里的key一定要和类里面属性名称相对应 */public static void main(String[] args) {String jsonstring = "{\"resultcode\":\"200\",\"reason\":\"successed!\",\"result\":{\"sk\":{\"temp\":\"36\",\"wind_direction\":\"西风\",\"wind_strength\":\"2级\",\"humidity\":\"50%\",\"time\":\"11:23\"},\"today\":{\"temperature\":\"30℃~38℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"南风微风\",\"week\":\"星期六\",\"city\":\"苏州\",\"date_y\":\"2016年07月23日\",\"dressing_index\":\"炎热\",\"dressing_advice\":\"天气炎热，建议着短衫、短裙、短裤、薄型T恤衫等清凉夏季服装。\",\"uv_index\":\"很强\",\"comfort_index\":\"\",\"wash_index\":\"较适宜\",\"travel_index\":\"较适宜\",\"exercise_index\":\"较适宜\",\"drying_index\":\"\"},\"future\":[{\"temperature\":\"30℃~38℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"南风微风\",\"week\":\"星期六\",\"date\":\"20160723\"},{\"temperature\":\"30℃~38℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"东南风微风\",\"week\":\"星期日\",\"date\":\"20160724\"},{\"temperature\":\"30℃~38℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"东南风微风\",\"week\":\"星期一\",\"date\":\"20160725\"},{\"temperature\":\"30℃~39℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"西南风微风\",\"week\":\"星期二\",\"date\":\"20160726\"},{\"temperature\":\"30℃~38℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"西风微风\",\"week\":\"星期三\",\"date\":\"20160727\"},{\"temperature\":\"30℃~39℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"西南风微风\",\"week\":\"星期四\",\"date\":\"20160728\"},{\"temperature\":\"30℃~38℃\",\"weather\":\"晴\",\"weather_id\":{\"fa\":\"00\",\"fb\":\"00\"},\"wind\":\"东南风微风\",\"week\":\"星期五\",\"date\":\"20160729\"}]},\"error_code\":0}";System.out.println(jsonstring);Gson g = new Gson();JsonResult result = g.fromJson(jsonstring, JsonResult.class);//将字符串按照JsonResult作为模板解析，返回JsonResult对象


ResultTest r = result.getResult();//通过JsonResult获取结果集内容List<JsonFuture> list = r.getFuture();//在结果集内容里面获得未来几天的天气JsonFuture j = list.get(0);//获取第一天的天气情况System.out.println("温度："+j.getTemperature());}}

package com.share.test_4_11;public class JsonResult {private ResultTest result;public ResultTest getResult() {return result;}public void setResult(ResultTest result) {this.result = result;}}

package com.share.test_4_11;import java.util.List;public class ResultTest {private List<JsonFuture> future;public List<JsonFuture> getFuture() {return future;}public void setFuture(List<JsonFuture> future) {this.future = future;}}

package com.share.test_4_11;public class JsonFuture {private String temperature;private String weather;private JsonWeather_id weather_id;private String wind;private String week;private String date;public String getTemperature() {return temperature;}public void setTemperature(String temperature) {this.temperature = temperature;}public String getWeather() {return weather;}public void setWeather(String weather) {this.weather = weather;}public JsonWeather_id getWeather_id() {return weather_id;}public void setWeather_id(JsonWeather_id weather_id) {this.weather_id = weather_id;}public String getWind() {return wind;}public void setWind(String wind) {this.wind = wind;}public String getWeek() {return week;}public void setWeek(String week) {this.week = week;}public String getDate() {return date;}public void setDate(String date) {this.date = date;}}

package com.share.test_4_11;public class JsonWeather_id {private String fa;private String fb;public String getFa() {return fa;}public void setFa(String fa) {this.fa = fa;}public String getFb() {return fb;}public void setFb(String fb) {this.fb = fb;}}